I just got over a strep infection in which I was prescribed penicillin for a swollen lymph node associated with this. It worked pretty well. For about a week after that I felt a little achy and sick but all good. The past couple days though I have noticed paler stool with undigested food from very last mean and some pain in lower right abdomen. The main is nothing major and sometimes un-noticable. I am worried I might have cancer.